408 Messrs. Aider and Hancock on a proposed New Order 



backwards and towards the right side, ends in the anus [i), which 

 is median, and a httle behind the centre of the body. 



At first we could scarcely determine the position of this organ, 

 though we had traced the intestine almost to its termination ; 

 and, notwithstandmg that there is at this part of the back a 

 swelling indicating its presence, yet there is no prominent nip- 

 ple, and it is very difficult to see the opening. The position of 

 the anus however was made manifest by our observing excre- 

 mentitious matter passing out of it, and its situation cannot 

 therefore be doubted. We succeeded in gaining further proof of 

 the position of this excretory orifice by using the compressor, so 

 as to force the contents of the intestine through it. This was 

 attained by placing the animal in the instrument with its dorsal 

 ridge exactly in profile, and then adjusting the pressure, with 

 great care, to avoid rupture. In this way we, more than once, 

 forced out the contents of the intestine. 



Along each side of the back immediately below the skin, and 

 distinct from it, is a wide, somewhat foUiculated, and branched 

 vessel (g, g, g, g), having the interior lined with a layer, more or 

 less thick, of dark green granules. These vessels are joined to 

 the sides of the upper surface of the stomach, which is nearly 

 covered with the granular substance. In these vessels we think 

 we perceive the true homologue of the liver of the more typical 

 mollusks ; and in proof of this opinion we would refer to the na- 

 ture of their contents, which, as just stated, are green and gra- 

 nular. When these granules are highly magnified, each is found 

 to be an aggregation of very minute corpuscules within a delicate 

 membranous vesicle, having much the character of the micro- 

 scopic structure of the glands of the papillse of Eolis. 



In Cenia and Acteonia the digestive system would appear to 

 be similar to that of Limapontia ; both are furnished with a mus- 

 cular buccal mass without jaws, but having a lingual apparatus 

 formed as in Limapontia ; the hepatic organ has the same dispo- 

 sition as in that genus ; and the anal aperture in both is indicated 

 by a slight swelling on the median line near the centre of the 

 back, though we have not determined its position in these two 

 genera with the same precision as in Limapontia. 



This account of the alimentary system is very different from 

 that given by M. de Quatrefages in the description of his Cha- 

 lidis ccerulea. The anus and intestine he has altogether over- 

 looked, and the two lateral hepatic vessels he has called the 

 stomach, that organ having likewise escaped his observation : 

 there can be no doubt, however, that C. carulea is as highly or- 

 ganized as L. nigra. 



The Generative System lies immediately beneath the organs 



